Propellant powder and process of making the same



' Patented Apr. 23, 1929.

ARTHUR ONEIL,.OF ALTON, ILLINOIS, ASSIGNOR TO WESTERN CARTRIDGE COM- rm, OF EAST ALTON, ILLINOIS, A CORPORATION OF DELAWARE.

rnorELLAnr rowmm AND rnocnss or MAKING THE SAME,

I in Drawing. Original application filed June 20, 1924, Serial No. 721,203. Divided and this application filed October. 12, 1925. Serial No. 62,090.

This invention relates to progressive powders, and more particularly to progressive burningpropellant powders adapted for use in small arms such'as'shot guns. This application is a division of my application Serial Number 721,203, filed J une, 20, 1924. The rate of burning of a powder grain is dependent upon its density. Thus a nitrocellulose powder grain of comparatively low density, such as the bulked-smokeless powder described in my Patent No. 1,627,861, issued May 10, 1927, or even ordinary bulk smokeless powder, has a higher rate of burning than, for instance, condensed colloided nitrocellulose powder.

One of the objects of this invention, therefore, is to provide a progressive burning powder consisting of blended grams, the

. densities of which are so chosen as to cause a blended charge thereof to burn progressively.

Another object is to provide a progressive burning-powder consisting of blended portions, in which each portion has a graindensity and composition which is difl'erent from that of the other, the characteristics of the several portions being so chosen as to cause a blended charge thereof to burn progressively.

Further objects will appear from the detail description in which will be disclosed an illustrative embodiment-of this. invention.

In accordance with this invention a powder is produced by selecting powder portions so that the grains of the several portions burn at progressively'decreasing rates and the portions so chosen are then blended in the desired proportions so as to roduce the desired progressive burning of a 'lended charge. While the grain densities of the same-portion may be substantially the same, the grain densities of the several portions vary progressively ina'ccordance with the desired progressive action of a blended charge.

In accordance withan embodiment of this invention, the rate of burningis controlled by proper selection of the grain density.v

Thus by proper selection of, for instance, a portion of dense colloided nitro-cellulose owder and a portion of bulk smokeless power, or a bulked nitro-cellulose powder, such, for instance, as described in my Patent No. 1,627,861, the desired progressive burning action may be obtained. The following Is an I 9% dinitro-toluene.

5% dinitro-toluene.

ties of the portions of the blen and compositions of the portions of the blendexample of a rifle powder in which the grains may be of uniform size and the base nitrocellulose:

80% high nitration powder coated with 10% low nitration powdercoated with 10% low nitration powder-uncoated.

The above blended mixture produces velocities equal with thefirst 80% component of the mixture above, but with a smaller charge. It is also adapted for shot shells, provlding granulations suitable for shot shell powders are selected.

In accordance with this invention, therefore, the progressive burning action is pro duced by proper selection of the grain densied charge; and by the proper selection of the proportions of the charge portions the desired ,progressive burning can be. obtained. In accordance with this invention the more rapid burning powders impart their energy ,di

rectl to the slower burning constituents of the mixture and there is no localizing of pressure but rather a uniform increase in-the rate of burning whichin turn imparts a sustained drive to the projectile.

. It will be noted that inthe example given, not only has each portion a grain density which is different from that of the other, but

the composition of each portion is also dif- 'ferent from that of-the other. Accordingly,-

by proper selection of both grain densities ed charge and by proper selection of the proportions of thecharge portions, the desired progressive burning can be obtained. While in the specification and-claims the term grain is used, it is to be understood that it is intended as a word of general description and not of limitation, but to. include the various forms in which powder is produced for use. It will be further undervstood that while theories of formation and operation have been advanced,the invention 1 is not necessarily limited thereto.. It will further be obvious that various changes may be made in details withoutdeparting from' the spirit of this invention; it is, therefore, to be understood that this invention is not to be limited tothe specific details described. Having thus described the invention, what is claimed is:

.blended portions,

' 1. A progressive burning powder consisting of blended grains, the densities of which are so chosen as to cause a blended charge thereof to burn progressively.

2. A'pro ressive burning powder consisting of blen ed portions, each portion having a grain density which is difl'erent from that of the other, the densities of the grains of the several portions being so chosen as to cause a blended charge thereof to burn progressively. p

3. A progressive burning powder consist ing of blended portions, the densities of the grains of each portion being substantially the same but the grain dens1t1esof the several portions being so chosen as to cause a blended charge thereof to burn progressivly.

4.A progressive powder consisting of each portion having a grain density which is diflerent from that of the other, the densities of the grains of the several portions being so chosen as to cause a blended charge thereof to burn progressively.

5. A progressive burning powder consisting of blended portions, each portion having a grain density and composition which is different from that of the other, the characteristics of the several chosen as to cause a blen to burn progressively.

6. The process of making rogressive burning powder consistin in lendin powder portions in which the density of eac portion is'difi'erent from that of the other and so choosing the densities of the grains of the several portions as to cause a blended charge thereof to'burn progressively.

7. The rocess of making progressive buming pow er consisting in blending portions in which the density of each portion is different from that of the other and so choosing the densities of the grains of the several 01''- tions and the relative proportions of t ese' portions as to cause a blended charge thereof to burn progressively.

portions being so edcharge thereof 8. The process of making progressive powder consisting in selecting powder portions so that the grains of the several portions are of progressively increasing densities and blending the portions.

In testimony whereof I afiix my signature this 25th day of August, 1925.

ARTHUR s. ONEIL: 

